Test handle



R. A. HAIGH TEST HANDLE March 12, 1957 I5 Sheets-Sheet 1 Filed Dec. 16,1953 INVENTOR i/l #az'yfi.

March 12, 1957 R. A. HAIGH 2,785,258

TEST HANDLE Filed Dec. 16, 1953 s Shets-Sheet 2 INVENTOR I RA flaz yfi.

' i BY ATTo EY R. A. HAIGH TEST HANDLE March 12, 1957 3 Sheets-Sheet 5Filed Dec. 16, 1953 United States Patent O 43 253 TEST HANDLE Ru n Haiswas, APP iQafi n D cembe 26 5 e a No 398,492

' 7 9 Clai s- (or. 20.0-15.1)

This invention relates to a test handle structure for ground test boxes.I

Ground test" boxes now in conventional use embody a wheel supportedhousing within which are various electric devices including atranstormer and selector.

The housing is providedwith an electric plug-in cable and a pair ofoutlet cables, each of which is provided with a terminal handle by whichcontact is made with the'pa'rticular device to be tested.

Th'e'outle't cables are of substantial length and the handlesarepermanently united with the cables.

The handles necessarily embody major portions which areof insulating"material and accordingly do not have the capacity to withstandsubstantial impact without breakage thereof.

Thereferred to ground test boxes are used in many places wliere thehandles, are subject to substantial impact even under the usual care byan operator. On the other hand, such handles are carelessly dropped orotherwise roughly handled with the result that some are H broken.

Since such handles are permanently connected with the cables, breakageof a handle requires not only a new handle but a complete relativelylong cable with a handle afttached. l

Thus, with the conventional test box construction, breakage of a handleentails considerablefinancial loss aswell as a'ldssj of time requiredfor the replacement of a unitary cable and handle."

It is "accdrdinglya primary object of this invention to provide ahandlefor an output cable of a ground test.

box which is detachabl'y connectable with the cable whereby upon'breakage of the handle, a new handle may readily be substitutedtherefor'with a retention of the cable. i

A further object of the invention is toprovide a handle which not onlyhas provision for detachable connectionwith anoutputcable of a groundtest box but which of itself comprises readily separable parts, wherebyupon breakage o f 'one or more parts, same may readily be replaced,withoutthe. necessity of providing an entire new l Other objects andadvantages of the invention will become apparent in thecourse of thefollowing detailed description, taken connection with the accompanyingdrawings, wherein:

Fig. 1; is; an axial sectional view of the tubular handle body.

BracketedFig. 2 is an isometric exploded view wherein the cooperatinghandle elements are shown in a designa'te'd'order' of assembly Withinand upon the handle body.

Fig. 3-isia engagemen view of the complete haudle s'tructure inaccordance with a preferred structural mbqdime t ls iof-v Fig; 4,v s. anend elevationalview asobserved from the.

lef t'o f Fig. 3.. "ivitlitth'ej cabl eibeing. omitted Patent M 2 ,95

ice

fig. 5 is a transverse sectional view as observed in the plane of 5T5 onFig. 3.

Fig. 6 is a longitudinal axial sectional view of the improved handle.

Fig. 7 is a broken diagrammatic top plan view of a conventional test boxwith which the improved handle in accordance with the present inventionis used.

Fig. 8 is an isometric View disclosing a slight modification of theinvention.

For a better understanding ofthe purpose of the present invention,reference will first be made to Fig. 7 wherein the diagrammaticallydisclosed test box T. includes a generally rectangular control enclosingand supporting housing H which is supported on wheels W fortransportation thereof from one testing position to another.

The control means includes selectors S and pilot lamps L.

The housing is provided with an electric plug-in cable C and is alsoprovided with a pair of outlet cables C and which are provided withterminal handles h.

The purpose of a test box which is generally understood by those skilledin the art is to ground test structures, such as generators, electricfans and the like and in the testing operations, the handles provide thetest leads which embody picks whose free ends are engaged with thestructures being ground tested. a

The cables C indicated as broken in Fig. 7 are in practice ofsubstantial length for unobstructed movement of the handles h to desiredtesting positions.

While the. handles, with which test boxes have heretofore been provided,satisfactorily fulfilled their functions so far as ground testing wasconcerned, it has been observed that such handles often receive roughusage and are often dropped resulting in same being broken and renderedunserviceable.

1n the test box structures now in use, the long cables- C are providedwith handles which are in eifect unitary therewith whereby upon breakageof a handle, same together with the entire cable C mustbe replaced.

The improved handle. in accordance with the; present invention and;which wholly overcomes the above noted objections to existing handles,comprises a tubulan han: dle body 19 which, as indicated in Figs. l and6, includes inner and outer, tubes 11. and 12 respectively which are ofelectrical insulating material and which are of equal length but ofdifferent diameters leaving a space therebetween, and a shorter metaltube 13 is disposed within the space between the tubes 11 and 12.

The purpose of the metal tube 13 is to reinforce the tubular handle bodyand render same immune to break ing upon impact with another body.Suitable insulating. collars 14 may be disposed between the inner andouter insulating tubes 11 and 12- at the opposite ends thereof and alldescribed parts of the tubular handle body are suitably adhered into aunitary structure. The various elements entering into the. handlestructure and which are operatively associated with the handle body willbe The sleevelS: is provided with an arcuatenotch 16 which in assembledposition with the handle bodyaligns- Witha corresponding-notch 17: invthe tubularhandle body.

The ,opposite, ends of? the. sleeve 15 provide positioningt.

shoulders 1.18 -and 19 fm? a.- purpose .to be referred to.

A dish; 29 is providerln with-.acentral aperture 21;:for.

' of the cable C.

receiving the tubular handle body and prior to the assembly of the disksame is provided with a microswitch 22 having a depressible switchbutton 23 and which is secured to the disk by means of a pair of screws24 which extend through apertures 25 'in' the micro-switch and whosefree ends are engaged in tapped apertures 26 in the disk. i

A finger engageable switch operating member 27 is pivotallysecured tothe disk by means of a screw 28 extendable through a sleeve 29 disposedwithin an aperture 30 in the member 27 "and through an aperture 31 inthe disk.

A retracting spring 32 has one end thereof secured to the switchoperating member 27 and the opposite end of the spring bears on sleeve15 in the assembled positionof the disk. A stop pin 27 projects from thedisk and limits retraction of member 27.

With the micro-switch 22 and operating member secured to the disk 20 asabove described, the disk is entered over the right hand end of thehandle body 10 until the face of the disk surrounding the centralaperture -21 therein engages the shoulder 18 on sleeve 15. V In thepositioning of the switch equipped disk as above, a key 33 which isthreaded into a tapped opening 34 in the handle body ltlis receivedwithin a keyway 35 open the handle for exposure of leads 38. 'With thecable then prepared, it is drawn through the handle body 10 from left toright with respect to Fig. 6 and is provided with a winding of tape 39which upon subsequent drawing of the cable from right to left engagesthe inner end of sleeve 36 Which, together with the tape winding,precludes the handle from being withdrawn from the adjacent end With thecable in proper position, the exposed end wires 40 will project slightlyin advance of .the right hand end of the handle body 10.

After the cable is thus positioned, the leads 38 are drawn through thealigned notches 16 and 17 and secured to the screws 24.

After the cable has thus been connected to the microswit-ch 22, a collar41 is moved over the left hand end of the body It! until the advanceedge thereof engages the,

disk 28, the collar being of a circumference to circumscribe themicro-switch 22 and the switch operating member 27 as is indicated inFig. 5.

A second disk, 42, having a central aperture 42 is next moved over theleft hand end of body 10 until it contacts the adjacent edge of collar41 and shoulder 19 and thereafter a plurality of screws 43 are extendedthrough countersunk openings 44 in the disk 42, and which screws havetheir threaded ends engaged within tapped openings 45 in the disk 20.

It will be observed from Fig. 5, that the three screws 43 are disposedexternally of the collar 41 and since the collar and the disks are ofinsulating material, the screws are effectively insulated from theswitch and the wiring, whereby the usual practice of directly insulatingthe screws is wholly overcome; Furthermore, the collar and the disksprovide a housing for the switch which is prevented from axial movementby the sleeve 15 and from rotative movement by the key'33 and thecooperating keyreadily removable parts and which comprise a sleeve 47 '4of insulating material receivable within the right hand end of the body10.

The sleeve 47 is provided with tapped openings 48 in which arereceivable the inner ends of a plurality of screws 49 whichareextendable through countersunk openings 50 in the right hand end ofthe tubular body 10.

An externally threaded tubular member 51 has one end portion thereofthreadedly engaged with the inner wall of sleeve 47 and the otherprotruding end portion is provided with diametrically opposed slots 52through which the wire ends'40' are extended as indicated in Fig. 6.

A pair of nuts 53 are threaded onto the slotted end of member 51 withthe wire ends 40 clamped between the same.

A pick member is threaded onto the member 51 externally of the outermostnut 53 and the same comprises a nut member 54 to the outer end of whichis rigidly secured a pick 55.

In the modified construction shown in Fig. 8 the sleeve 15 is providedwith an integral lug 56 which provides a key receivable within thekeyway 35 in thedisk 20, which does away with the tapped opening 34 andthe threaded key 33. i 7

While as indicated in Fig. 7, two handles h are provided and which arereplaced by the handle of the present invention, only one of suchhandles isprovided with a switch, and the two handles being otherwise oflike construction.

It should be appreciated from the foregoing disclosure,

that by the present invention, a handle for ground test boxes isprovided which provides for ready replacement of an entire handle or oneor more of the several removable elements entering into the handleconstruction.

While I have disclosed my invention in accordance with a single specificstructural embodiment thereof, such is to be considered as illustrativeonly, and not restrictive, I the scope of the invention being defined inthe sub-joined claims. a

What I claim and desire to secure by U. S. Letters Patent is:

1. A handle for a ground test box having a relatively I 'long outletcable, comprising an elongated insulating tubular body for receiving oneend of the cable, means at one end of the tubular body for restrainingsame against movement toward the end of the cable, a pick removablysecured to the opposite end of the body, a

switch supported externally of the body. and intermediate cable, aswitch supported by thetubular body externallythereof, said tubular bodybeing provided with a-notch receiving leads from the cable forconnection to said switch, said switch being supported within a housingdis-i posed externally of said tubular body, and a'finger receiv ingopening in a wall of said housing for access to'saidr switch.

3. A handle for a ground test box having a-relatively long outlet cable,comprising an elongated tubular body; for removably receiving one end ofthe cable, means removably secured to the tubular body for securing sameto the cable, said tubular body comprising radially spaced inner andouter tubular members of insulatingmaterial,

an intermediate reinforcing tubular member of metal whose opposite endsare disposed axially inwardly of the corresponding ends of the tubularmembers, and an insulating collar disposed between said tubular membersat each end thereof.

4. A handle for a ground test box including a relatively long cablehaving the outer insulation layer thereof removed for a predetermineddistance from thefree end thereof for exposing a pair of leads spacedfrom the free end and bare wires at the free end; comprising arelatively long tubular body throughout the length of which an endportion of said cable is extended, a micro-switch supported by the bodyintermediate its ends and externally thereof and to which said leads areremovably connected, a unit removably secured to one end of said body towhich said bare wires are secured, said tubular body comprising a pairof equal length insulating tubular members disposed in telescopingrelation with a space therebetween, and a reenforcing metallic tubularmember of less length than said insulating tubular members disposedwithin said space and having its ends equally spaced from the ends ofsaid insulating tubular members.

5. A handle for a ground test box including a relatively long cablehaving the outer insulation layer thereof removed for a predetermineddistance from the free end thereof for exposing a pair of leads spacedfrom the free end and bare wires at the free end; comprising arelatively long tubular body throughout the length of which an endportion of said cable is extended, a micro-switch supported by the bodyintermediate its ends and externally thereof and to which said leads areremovably connected, a unit removably secured to one end of said body towhich said bare Wires are secured, a sleeve disposed within the otherend of said tubular body, and a winding of tape on said cable engageablewith the inner end of said sleeve for precluding removal of the handlefrom the cable.

6. A handle for a ground test box including a relatively long cablehaving the outer insulation layer thereof removed for a predetermineddistance from the free end thereof for exposing a pair of leads spacedfrom the free end and bare wires at the free end; comprising arelatively long tubular body throughout the length of which an endportion of said cable is extended, a micro-switch supported by the bodyintermediate its ends and externally thereof and to which said leads areremovably connected, a unit removably secured to one end of said body towhich said bare wires are secured, a tubular sleeve surrounding saidtubular body intermediate its ends, said sleeve and said tubular bodybeing provided with aligned notches through which said leads areextended, a pair of disks surrounding said tubular body, one engagedwith each edge of said sleeve, said micro-switch being removablysupported by one of said disks, a switch operating member pivoted tosaid last disk and the other disk being provided with an opening forreceiving a finger for actuating said switch operating member.

7. The structure according to claim 6, together with a collar disposedbetween said disks adjacent their peripheries, and a plurality ofcircumferentially spaced screws extended through said disks inengagement with the outer periphery of said collar.

8. A handle for a ground test box including a relatively long cablehaving the outer insulation layer thereof removed for a predetermineddistance from the free end thereof for exposing a pair of leads spacedfrom the free end and bare wires at the free end; comprising arelatively long tubular body throughout the length of which an endportion of said cable is extended a microswitch supported by the bodyintermediate its ends and externally thereof and to which said leads areremovably connected, a unit removably secured to one end of said body towhich said bare wires are secured, said unit comprising an insulatingsleeve removably supported within said one end of said body, anexternally threaded metallic member having one end portion thereofthreaded into said sleeve and the other end portion projecting from thesleeve and said one end of the body, said projecting end havingdiametrically opposed slots through which said bare wires are extended,a pair of nuts on said projecting end in clamping engagement with saidwires, and a pick member removably secured to said metallic memberoutwardly of said nuts.

9. The structure according to claim 8, wherein said pick member includesa nut member threadedly engaged with said metallic member and a pickrigidly secured to said nut member.

References Cited in the file of this patent UNITED STATES PATENTS1,970,232 Hady Aug. 14, 1934 2,450,597 Karnoski Oct. 5, 1948 2,641,630Goldberger et al. June 9, 1953

